building applications with mongodb - an introduction
DESCRIPTION
TRANSCRIPT
Nosh [email protected]@noshinoshhttp://mongodb.orghttp://10gen.com
Building applications with MongoDB – An introduction
MongoBerlin – March 25, 2011
Today’s Talk•MongoDB: Data modeling, queries,
geospatial, updates, map reduce
•Using a location-based app as an example
•Example Works in MongoDB JS shell
Application Goals
PlacesCheck
ins
(1)Q: Current locationA: Places near location
(2) Add user generated content
(3) Record user checkins
(4) Stats about checkins
Documents
doc1 = {_id: 4b97e62bf1d8c7152c9ccb74,key1: value1,key2: value2,
key3: {..., ..., ...},
key4: [..., ..., ]
}
Collections
doc1, doc2, doc3
Places Users Checkins
doc3, doc4, doc5
doc6, doc7, doc8
place1 = {name: "10gen HQ”,address: ”134 5th Avenue 3rd Floor”,city: "New York”,zip: "10011”
}
db.places.find({zip:”10011”}).limit(10)
Places v1
place1 = {name: "10gen HQ”,address: "17 West 18th Street 8th Floor”,city: "New York”,zip: "10011”,
tags: [“business”, “recommended”]
}
db.places.find({zip:”10011”, tags:”business”})
Places v2
place1 = {name: "10gen HQ”,address: "17 West 18th Street 8th Floor”,city: "New York”,zip: "10011”,
tags: [“business”, “cool place”],
latlong: [40.0,72.0]
}
db.places.ensureIndex({latlong:”2d”})db.places.find({latlong:{$near:[40,70]}})
Places v3
place1 = {name: "10gen HQ”,address: "17 West 18th Street 8th Floor”,city: "New York”,zip: "10011”,latlong: [40.0,72.0],
tags: [“business”, “cool place”],
tips: [{user:"nosh", time:6/26/2010, tip:"stop by for office
hours on Wednesdays from 4-6pm"}, {.....}, {.....}]
}
Places v4
Creating your indexesdb.places.ensureIndex({tags:1})db.places.ensureIndex({name:1})db.places.ensureIndex({latlong:”2d”})
Finding places:db.places.find({latlong:{$near:[40,70]}})
With regular expressions:db.places.find({name: /^typeaheadstring/)
By tag:db.places.find({tags: “business”})
Querying your Places
Initial data load:db.places.insert(place1)
Updating tips:db.places.update({name:"10gen HQ"},
{$push :{tips: {user:"nosh", time:6/26/2010,
tip:"stop by for office hours on Wednesdays from 4-6"}}}}
Inserting and updating places
Application Goals
PlacesCheck
ins
(1)Q: Current locationA: Places near location
(2) Add user generated content
(3) Record user checkins
(4) Stats about checkins
user1 = {name: “nosh”email: “[email protected]”,...checkins: [4b97e62bf1d8c7152c9ccb74,
5a20e62bf1d8c736ab]}
checkins [] = ObjectId reference to checkin collection
Users
checkin1 = {place: “10gen HQ”,
ts: 9/20/2010 10:12:00,
userId: <objectid of user>}
Check-in = 2 opsInsert check in object [checkin collection]Update ($push) user object [user collection]
Indexes:db.checkins.ensureIndex({place:1, ts:1})db.checkins.ensureIndex({ts:1})
Checkins
$set, $unset, $rename
$push, $pop, $pull, $addToSet
$inc
Atomic Updates
Application Goals
PlacesCheck
ins
(1)Q: Current locationA: Places near location
(2) Add user generated content
(3) Record user checkins
(4) Stats about checkins
Simple Statsdb.checkins.find({place: “10gen HQ”)
db.checkins.find({place: “10gen HQ”}).sort({ts:-1}).limit(10)
db.checkins.find({place: “10gen HQ”, ts: {$gt: midnight}}).count()
Stats with MapReduce
mapFunc = function() {emit(this.place, 1);}
reduceFunc = function(key, values) {return Array.sum(values);
}
res = db.checkins.mapReduce(mapFunc,reduceFunc, {query: {timestamp: {$gt:nowminus3hrs}}})
res = [{_id:”10gen HQ”, value: 17}, ….., ….]
res.find({ value: {$gt: 15},_id: {$in: [….., ….., …..]}
})
Application Goals
PlacesCheck
ins
(1)Q: Current locationA: Places near location
(2) Add user generated content
(3) Record user checkins
(4) Stats about checkins
Single Master Deployments
Primary/Master
Secondary/Slave• Configure as a replica set for automated
failover
• Add more secondaries to scale reads
Auto Sharded Deployment
Primary/Master
Secondary/Slave
MongoS
•Autosharding distributes data among two or more replica sets• Mongo Config Server(s) handles distribution & balancing
• Transparent to applications
MongoConfig
Use Cases•RDBMS replacement for high-traffic web
applications
•Content Management-type applications
•Social, mobile
•Real-time analytics
•High-speed data loggingWeb 2.0, Media, SaaS, Gaming, Finance, Telecom, Healthcare
MongoDB in Production
Nosh [email protected] of Product Strategy, 10genhttp://mongodb.orghttp://10gen.com
-We are hiring!-@mongodb
[email protected]@noshinosh